The template-assembled synthetic protein (TASP) concept of protein design is extended in the construction of protein-like packing topologies with multiply branched, oligocyclic chain architectures (\"locked-in folds\"). These synthetic macromols. exhibit unique physicochem. and folding properties and serve as versatile scaffolds in protein design and mimicry. Thus, a locked-in fold zinc finger motif mimic was prepd. by selective oxime formation between bicyclic peptide template I and helical 18-residue peptide OHCCO-Phe-Ser-Arg-Ser-Asp-Glu-Leu-Thr-Arg-His-Ile-Arg-Ile-His-Thr-Gly-Lys(COCH2ONHFmoc)-Gly-NH2, followed by oxidn. of the Ser residue in I for the corresponding glyoxylate deriv., Fmoc cleavage, and second oxime bond formation to give the desired template (II). II preserves the essential structural features of the native zinc finger mol. as shown by absorption and CD spectra and by its zinc complexation properties. [on SciFinder (R)]